Hydrocarbon fluids such as oil and natural gas are obtained from a subterranean geologic formation by drilling a well that penetrates the hydrocarbon-bearing formation. Once a wellbore is drilled, various forms of well completion components may be installed in order to control and enhance the efficiency of producing the various fluids from the reservoir.
Wellbores are frequently drilled using boring tools that break up rock or hard sections of the geological formation by mechanical action. Mechanical actions may include, for example, striking, gouging, or shearing. Due to the violent nature of mechanical actions, working surfaces of boring tools naturally degrade over time. To minimize degradation of the working surfaces of boring tools over time, the working surface is adapted depending on the type of mechanical action that the boring tool is expected to perform. Similar degradation of boring tools occurs in other drilling applications such as making blast holes for mining applications.
Working surfaces of some boring tools are a polycrystalline diamond (PCD) material known in the art for having a high degree of wear resistance. PCD materials that are known in the art are formed by compacting a powder including diamond grains and a catalyst into a green form that is then subjected to a high temperature, high pressure sintering process. Sintering at high temperature and high pressure activates the catalyst in the powder which in turn creates inter-diamond grain bonds and adheres the sintered PCD material to the boring tool. The sintered PCD material contains a microstructure of randomly oriented diamond crystals bonded together to form a diamond matrix phase and a plurality of interstitial regions interposed between the diamond crystals.
The material properties of a PCD material, such as fracture toughness or transverse rupture strength, are contributed to by both the diamond matrix phase and the residual catalyst material located in interstitial regions. However, measurements of bulk properties of a PCD material may hide information about the PCD material. For example, a PCD material including diamond grains that are very strongly bonded and a second phase that is weakly bonded may appear to have a transverse rupture strength that is the same as a PCD material that includes diamond grains that are weakly bonded and a second phase that is very strongly bonded.
Conventional wisdom from what is known in the art suggests that maximizing both the fracture toughness and flexural strength minimizes boring tool wear over time. However, the aforementioned suggestions only consider a limited number of potential failure mechanisms and does not consider how individual phases of PCD materials contribute to failure mechanisms. Improvements in PCD materials that take into account additional failure mechanisms may decrease tool wear and improve tool life.